The present invention relates to monitoring systems and more particularly to a method and system for monitoring gases used in semiconductor manufacturing at one or more sites from a remote location using the World Wide Web. This invention provides increased efficiency in monitoring the gases and results in improved efficiency in identification of alarms, responding to problems and reducing down time.
The manufacture of semiconductor devices involves the use of a variety of gases, which typically are toxic. The gases are contained in cylinders which are stored in cabinets. The gases are delivered to the tools during the manufacturing process under the control of a process gas delivery system. An example of a commercially available process gas delivery system is the GASGUARD(copyright) Network System from Air Products and Chemicals, Inc. The components of a typical process gas delivery system 50 are illustrated in FIG. 1, which comprises a gas cabinet 14, an optional manifold box 15, a network interface 13, two network adapters (not shown), and control software (not shown) which runs within a personal computer (PC) system 11. There are typically one or two cylinders of gas (not shown) within a gas cabinet 14. The gas cabinet 14 may be connected via gas lines (not shown) to a single tool 30, or preferably, through a manifold box 15. A manifold box 15 can provide a controlled feed of gases to typically as many as four tools 30. If one of the tools 30 requires maintenance, the flow of gases to a given tool may be shut off by using a gas isolation box (GIB) 20 which allows the other remaining tools 30 to remain in production while an individual tool is serviced. The use of a GIB 20 also permits gas pressure to be maintained in the gas line while a tool 30 is being serviced, so that the tool may be brought back on line quickly without having to re-pressurize the gas line. The GIB 20 is not part of the gas delivery system and is considered part of the semiconductor processing equipment.
In a typical semiconductor fabrication operation, a single gas delivery system may include well over a hundred gas cabinets 14 and manifolds 15 which are controlled from a control room 10. Each gas cabinet 14 and manifold 15 is in communications with the control room 10 through a network interface 13. The network interface 13 is in communication with software that is provided as part of the gas delivery system, and the software runs on one or more PC""s 11 located within the control room 10. For example, a typical GASGUARD(copyright) network may include between one or more PC""s 11 connected to a single network interface 13, and each PC 11 is capable of controlling well over a hundred units comprising a combination of gas cabinets 14 and mainfolds 15. The software provides numerous menus and functions to control, operate, and collect data from the gas cabinets 14 and manifolds 15.
In a typical semiconductor fabrication operation, wafer processing proceeds 24 hours a day, 7 days a week. Therefore, reliable delivery of process gases to the process tools 30 is required to maintain continuous production. The gas delivery system is designed to collect information about the status of the gases within the gas delivery system 50 and notify technicians and operators within the control room 10 in the event of any problems that may occur. Examples of problems include gas leaks, high or low pressure, high temperatures, etc. For example, a low pressure reading might indicate that a gas cylinder needs to be replaced. Data collected at regular intervals includes gas pressures and flow rates. Under normal operating conditions, such data need only be recorded infrequently. Because the gas is depleted from the cylinders slowly, pressure data need only be recorded once every 6 hours in a typical operation. However, an alarm condition may require immediate attention by a technician to correct a problem such as a gas leak. Thus, a technician who is required to be physically present in a given control room to monitor the gas delivery system data is largely unproductive, unless and until an alarm is signaled. Such gas delivery systems may be implemented in multiple buildings and at multiple sites across the world within given organization. In addition, the occurrence of conditions requiring the changing of gas cylinders or of alarms is unpredictable. This creates difficulties and inefficiencies in staffing the control room and in effectively tracking the status of gases and equipment across multiple sites.
One related system that provides for a distributed monitor and control system for gases within a building is discussed in U.S. Pat. No. 4,866,594 entitled xe2x80x9cGas Cylinder Monitor and Control Systemxe2x80x9d issued to David et al. on Sep. 12, 1989 (hereinafter referred to as the David patent). The David patent provides for a system to monitor gases within a given building by using distributed monitoring modules connected to a centralized control system that includes means for signaling alarms at distributed locations within the building. An alarm may be communicated automatically to an operator by using a radio pager system. The centralized control system may comprise a computer system that can process data collected from the distributed modules and can generate statistical reports which can be printed out in hard copy form. However, the David patent was not designed to work with multiple sites.
U.S. Pat. No. 5,265,032 entitled xe2x80x9cMethod for Controlling LP Gas Inventoryxe2x80x9d issued to Naresh P. Patel oh Nov. 23, 1993 (hereinafter referred to as the Patel patent) discloses a method of collecting information for controlling liquid propane (LP) gas inventory in tanks at multiple remote locations. The Patel patent discusses the use of a computer to collect inventory data from a sensors that indicate LP gas levels within the tanks. The method of communication disclosed is provided by an autodialer and modem using telephone calls to receive and transmit information. The Patel patent discusses the use of the computer to maintain data files, prepare reports, and send reports to a host computer, for the purpose of maintaining LP gas inventories and minimizing trips to refill the LP gas tanks. However, the Patel patent does not address the complexity of equipment and types of gases that must be monitored in a gas delivery system used for processing semiconductors.
Neither the David patent nor the Patel patent provides for access to a centralized database from the Internet, using the service facilities known as the World Wide Web (hereinafter referred to as the Web).
The Internet refers to the network of computers that arose out of the network created by the Advanced Research Projects Agency (ARPA) using the Transmission Control Protocol/Internet protocol (TCP/IP) as the method for providing communication between the computers on the network. A number of service facilities have been developed to access and transfer information across the Internet and one of the most popular is known as the World Wide Web (Web) Typically, a user would access data on the Web by interfacing with software known as a Web browser, running on a client computer that is connected from the Internet.
The capabilities of a Web browser may be enhanced by executing a small program, or applet, running within the environment of the browser. Such an applet may be written in any of a variety of programming languages, such as Java(trademark). Java(trademark), a trademark of Sun Microsystems, Inc., is an object-oriented, platform-independent programming environment. One way that Java(trademark) platform independence is achieved is by embedding the Java(trademark) run-time environment, known as the Java(trademark) virtual machine (JVM), within a Web browser. Java(trademark) programs are compiled in byte format, which may be downloaded from a server and then interpreted by the JVM running within the Web browser. Thus, a program embodied as a Java(trademark) applet has the flexibility of being available from any computer system having a Java(trademark)-enabled Web browser and connected to the Internet.
It is an object of the present invention to allow process gas technicians to quickly and efficiently monitor and detect process gas problems at any manufacturing site or building, from any control room, office, home or any location where the Internet may be accessed, so that technicians do not have to be physically present in the control room where the gas monitoring system is located, and technicians may be employed when and where they are actually needed.
It is another object of the present invention to provide production operators, maintenance technicians, equipment engineers and managers access to information about their production tools to view current gas readings, events, or alarms.
It is another object of the present invention to provide access to information about all the gases throughout a site or across the enterprise so that the process gas services department can better manage and monitor their numerous distributed gas systems.
It is another object of the present invention to provide users with statistics related to the time of equipment failure and repair in order to improve the possibility of preventative maintenance.
It is another object of the present invention to provide users with automated reports and views of numerous process gas and/or tool statistics that are not currently available today or are manually produced today.
According to a preferred embodiment of the present invention, raw data comprising information such as tool pressures, tool status and alarms, gas cabinet events, and historical installation data, and similar data that is generated by a local Process Gas Control System is stored on a local computer system, such as a personal computer (PC).
According to a preferred embodiment of the present invention the local computer system also comprises a program that transfers the stored raw data to a server computer system located on a local area network (LAN). The transfer of data may be performed according to a prescribed schedule.
Also according to a preferred embodiment, the server computer system comprises a parser program that reads and parses the raw data and loads critical data into a database on the server. Commercial database software (for example, DB2(copyright) in the preferred embodiment), may be used to create and maintain the database. The database of the present invention may be accessed and queried by means of a secure connection from the Internet.
Also, according to a preferred embodiment of the present invention, the server further comprises an automated notification program that monitors the database according to predetermined warning limits, and if said warning limits are reached or exceeded, the notification program sends out notifications to a person selected from a list of qualified personnel having a notification device. Such a notification device could be a pager device, a Personal Digital Assistant (PDA), a Web enabled cellular device, or any similar device.
The present invention also comprises a program (such as a Java(trademark) application) that provides authorized personnel secure access to the gas process data through the Internet. The access is provided through a Web browser interface from which the authorized user may query any information of interest located in the database on the server computer system. The present invention also allows the user to request a variety of reports to be displayed and formatted within a Web browser frame.
The novel features believed to be characteristic of this invention are set forth in the appended claims. The invention itself, however, as well as other objects and advantages thereof, may be best understood by reference to the following detailed description of an illustrated preferred embodiment to be read in conjunction with the accompanying drawings.